Selective signaling system.



APPLICATION FILED APP-.30, 1912A Patented Dec. 8, 1914.

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0. T. LADEMAN. SELECTIVE SIGNALING SYSTEM.

APPLICATION TILED APILSO, 1912.

Patented Dec. 8,1914.

2 SHEETS-61113111 2 azazifl i i?" 59 WV W2 gm) U i TED: STATES PA OTTO T. LADEMAN, 0F MILWAUKEE, WISCONSIN, ASSIGNOR T0 MORSE COIDE SIGNAL COMPANY, OF MILWAUKEE, WISCONSIN.

SELECTIVE SIGNALING SYSTEM.

Specification of Letters Iatent.

Patented Dec. 8, 1914.

Application filed April 30, 1912. Serial No. 694,215.

To all whom it may concern:

Be it known that I, OTTO T. LADEMAN, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of \Visconsin, have invented a certain new and useful Improvement in Selective Signaling Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to selective signaling systems and has for its object the provision of an improved selective system of the stepby-step variety.

My invention has a number of different uses and can be readily applied, but in the description herein I will describe a form of police system in connection with which my invention is of great utility, the description being illustrative of my invention. In police systems it is customary to radiate the number of circuits outwardly from the central station and these circuits are provided with suitable visual or audible signals so that a patrolman in any district may be called to the particular patrol box from which he may communicate by telephone with the central station. Usually a number of signals on the same circuit respond to the same calling signal or code number, if one is used, so that the patrolman may more certainly become aware of the desire on the part of the central oifice to summon him for communication. Most of these telephone systems as at present installed, are of the central energy or common battery variety and one prime object of my invention is to provide a selective signal receiving device which can be satisfactorily used on a common battery telephone line in such a way as not to permit the common battery to leak, herein permitting of the installation of means to obstruct or substantially prevent the flow of common battery, the particular device used herein being a condenser.

My invention contemplates suitable pr0- visions so that the installation of this condenser will not injuriously influence the operation of the signal receiving device.

My system is also so arranged that suitthe particular device shown able telegraphic signals may be transmitted over the circuits without interference for the purpose of receiving the incoming patrolmans reports.

I will explain one embodiment of my invention as applied more particularly to such a police system in connection with the accompanying drawings, in which:

Figure 1 is a side view of an improved selector constructed in accordance with my invention, the casing whereof is shown in section; Fig. 2 is a partial sectional view on line aa of Fig. 1; Figs. 3, 4, 5 and 6 are views illustrating the various operative positions of a movable element of the device,

and Fig. 7 is a diagrammatic circuit arrangcment showing the inclusion of the se lector in a signaling system.

I will describe firstly a specific embodiment of a selector which may operate in accordance with my invention by particular reference to Figs. 1 to 6 inclusive. This selector operates in general along the lines set forth in the patent to WV. S. Burnett, No. 970,180, issued Sept. 13, 1910. I thus have two coils 1, 1 forming a single winding which magnetizc two separate and distinct magnetic circuits. The first magnetic circuit consists of the essentially C-shaped core 2 whose legs pass interior-1y of the coils 1, 1 and terminate in pole pieces 3, 3 and thus form one magnetic circuit; the other magnetic circuit comprises the heel piece 4 and the cores 5, 5 which project through the coils 1, 1. An armature 6 oscillatingly mounted upon pivots 7 7 is associated with the cores 5, 5 and this armature is polarized by the permanent magnet 7 so that this armature 6 occupies either one or the other of its two alternative positions, depending upon the polarity of the current last impressed on the coils 1, 1. An alternating current through the coils 1, 1, will of course oscillate the armature 6 with a frequency equal to the frequency of the impressed alternating current provided naturally the frequency is not too high to permit the said armature (5 to follow properly. A second armature 8 is mounted in close proximity to the pole pieces 3, 3 and is secured to a swinging element 9 pivoted at 10, which swinging element by reason of its overweight 11 tends normally to occupy the position shown in Fig. 2. When any character of current, however, is impressed on the coils 1, 1, whether alternating or direct, the swinging element 9 is rotated contra-clockwise (Fig. 2) a few degrees sufficient to withdraw a projection 12 of this swinging element away from a rotatable plate 13, and likewise sufficient to close contact between springs 14 and 15 through the agency of the insulating button 16 preferably fastened to the spring 15 and abutting against this swing ing element 9. This swinging element 9 has its central vertically arranged portion preferably plate shaped and the armature 8 forms a segmental piece at right angles to this plate shaped portion 9 so that this armature 8 is substantially parallel to the pole pieces 3, 3.

The magnetic elements above referred to are all suitably mounted upon a supporting plate 17 to which a hood 18 may be fastened so as to entirely inclose the working. portions, binding posts such as 18 and 19 being provided to carry the circuit from without to within the inclosed portion of the device. The swinging element 9 likewise carries a pin 20 whose purpose will be explained later. A framework 21. of non-magnetic material is suitably secured between the cores 5, 5 by means of the screws 35, 35 and carries certain operating parts as will presently appear. An openin 22 in this framework permits the pin 20 to project therethrough freely. The rotatable plate 13 is provided with a notch 23, which notch is angularly displaced in the different selectors corre sponding to different substations, to thereby control the selective feature of the device. This plate 13 is pivotally mounted between the framework 21. and an upright 24 secured to the framework 21, a shaft 25 being provided for this purpose. This shaft 25 likewise carries a toothed wheel 26 and a pronged plate 27, which plate 27, plate 13 and Wheel 26 are securely fastened to the shaft 25. The plate 27 has three projecting elements, one an. arm 23 which is used to come into contact with the pin 20 when the devices are being restored to their normal position; an arm 29 adapted to contact with a pointer 30 fastened to the armature 6 and movable therewith so as to prevent further operative rotation ofthe wheel 26 by the armature 6 when the arm 28 engages the pin 20; and an L-shaped arm 31 projecting toward the periphery of the plate 13 and then downwardly therefrom so as to be engaged by the projection 12 after the entire signaling and restoring operation has ceased, so as to move the shaft 25 a space of one-half cycle into its initial starting position to thereby carry the arm 28 out of the path. of the pin 20. The downwardly projecting portion of the arm 31 is more clearly illustrated in Fig. 6 from which it will be apparent that when this cam shaped projection of the arm 31 is engaged by the projection 12 of the movable element 9 that the movable elements carried by the shaft 25 are rotated a short space to bring them to their starting position.

In order to set the device an escapement lever 32 is provided which is secured to the shaft 33 pivotally mounted between the standard 24.- and the framework 21. This lever 32 has the arms 34., 34, whereby an oscillation of this arm causes a rotation of the shaft 25 by reason of the engagement of the prongs of the arms 3 1 with the toothed wheel 26. This is along the general lines of well known escapement mechanism and need not probably be further explained here.

In the operation of my device 1 utilize preferably alternating currents or their equivalent and each cycle of current, that is, one positive and one negative impulse moves the rotatable "elements one step. Thus for each cycle there is one engagement between the wheel 26 and each one of the prongs carried by the arms 34:. Naturally if but a half cycle is sent of such polarity to reverse the position of the armature 6, then the movable elements rotate but one-half step. This oscillating arm 32 is oscillated by means of a pin 36 carried by the arm 30. Thus whenever the armature 6 oscillates, the escapement arm 32 is oscillated and thereby the selective elements of the device are rotated therein. Now assume that the device is in the position shown in Fig. 3 which is the starting position, assuming also that the armature 6 is in the position shown in Fig. l as the armature is always supposed to 00- cupy a normal position on one side by reason of the fact that the last impulse always to be sent out is supposed to be of a given predetermined polarity. It is likewise assumed that the slot 23 is placed in such a position that two complete cycles must be sent in order for this particular device to respond. Assume then that two complete cycles, that is, two positive and two negative impulses are received by the armature, then each arm of the escapement mechanism will have engaged the wheel 26 twice and it will have moved four half steps. The initial impulse likewise rotates the swinging element 9 in a contra-clockwise direction so that its projection 12 is away from the periphery of the wheel 13 and it remains in this, position during the sending of the impulses. After the impulses have finally ceased, this arm 9 swings around by reason of the weight 11 and the projection 12 enters the notch 23 in which position, circuit is closed between springs 14 and 15. Of course, only those devices respond in which the notches directly register with the projection 12 as shown in Fig. 4, because in the other devices the projection merely falls against the periphery of the wheel 13 and in-such a position the contact between the springs 14 and 15 is not closed.

Assuming now that the station has been called and it is desired to restore the devices to normal, then additional impulses are sent to move the rotatable element progressively around so as to complete its rotation back to its starting point; The armature 6 is thereby oscillated by additional impulses, the first impulse having withdrawn the projection 12 from the notch 23 and these impulses are sent in a number exceeding the number required to complete the rotation back to the starting point of thewheel 26. The element 9, however, being inits attracted position has pushed the pin 20 into the path of the arm 28 as shown in Fig. 5 and thus the movable elements move only to the position indicated in Fig. 5, irrespective of the excessive number of cycles received. In this position illustrated in Fig. 5 the arm 30 likewise is opposite the arm 29and even though excessive cycles are received the escapement element 32 no longer engages the teeth of the wheel 26 as the armature 6is prevented from moving its required operative distance by the engagement of itsarm with the stop 29. Finally, however, the impulses cease, leaving the armature 6 in the position shown in Fig. 1 and likewise permitting the swinging element 9 to assumethe position shown in Fig. 2. While this element 9 is assuming this position, its projection 12 engages the cam shaped portion of th arm 31 and rotates the movable elements a half step into the position shown in Fig. 3, at which time the arm 28 is beyond the pin 30 and the projection 12 again rests against the periphery of the wheel 13. The notch is so chosen so as to make the particular instrument responsive to a certain number of cycles.

The selector illustrated in Figs. 1 to 6 inclusive is utilized at each substation and has its casing 18 added to the lower portion of a lantern casing 37, the selector being indi-;

cated diagrammatically by its coil 1, the ro-,

tatable element 13, the contacts 141: and 15 and the switching element 9. An overhanging hood 38 of the lantern casing 37 protects the casing 18 and the contained parts from moisture. Within the casing a suitable lamp 39 is provided whose indications are visible through a plurality of lenses 410 and this lamp has its circuit under the control of the springs 14. and 15, suitable line wires 11 and 42 leadingto a light circuit usually available to operate the lamp 39. WVhenever the contact between springs 14 and 15 is closed therefore, the lamp 39 will burn. The coil 1 of the selector is serially included with a condenser 43 arranged in circular form, the lead in wires 44 and 45 for this circuit including the selector and condenser being in bridge of the line wires 46 and 4721s will be seen from the illustration. At each substation likewise there is a lightning arrester 4.8 and a telephone set 49, of the central energy type or otherwise. There is likewise provided at each substation a diagrammatically indicated telegraphic code wheel 50 to close circuit through springs 51 and 52 in accordance with a prescribed code so that when this wheel 50 is rotated a distinctive signal is transmitted to the central station to indicate thatthe patrolman is sending in his report. At the central station I have a telephone set 53 for the operator whichby means of the key 54 may be connected in bridge of the line wires 46 and 47, the operation of which key 5 1 at the same time connects to the line wires 46 and 47 a common battery 55 which through the agency of a relay 56 is used not only for talking purposes but also to operate the line lamp 57 or the night bell 58 as well understood in accordance with telephone practice. The key 54 at the centralstation thus serves to connect the talking appliances in bridge of the line circuit 416. 47. is provided at the central station, which when operated connects a counting pole changer together with a battery 60 and a condenser 61 across the line wires 46 and 47 to send the necessary cycles of current to operate the step-by-stcp devices at the substations. It may be said that the details of my improved counting pole changer are set forth in my co-pending application Serial No. 690,727, filed April 15, 1912. This counting pole changer has a shaft 62 which is adapted to be rotated a given number of times depending upon the number of cycles it is desired to send by means of suitable counting mechanism set forth in my co-pending application. This shaft 62 has two conducting rings 63 and 61 mounted on said shaft but insulated therefrom and also has secured thereto two commutator segments and 66 separated by insulation 67. The rings 62-3 and 64 are connccted to the segments 65 and 66 respectively. Brushes 67 and 68 lead to the opposite terminals of the battery 60 while a brush 69 leads to the line wire 47 and a brush 70 leads to the line wire 46 through the interposition of the key 59. The condenser 61 bridges the break to take the discharge as well understood.

I. have found in practice that the inter position of the condenser 13 at the substation may cause difliculty in the operation of the selector device and the same is true as regards to condenser 61, in that, these con- A secondv key 59 spective commutator segments so that when the key 59 is operated prior to operating the counting pole changer, the condensers 61 and 43 receive a preliminary charge by virtue of the polarity impressed on the line wires 47 and 46. Thus the first impulse sent will not be needed to charge. the condensers as they, are already charged. Likewise the polarity of the common battery 55 which is normally on the line is of such character as to maintain this particular charge of a given polarity in the condensers so that these condensers, except when alternating cycles are being sent, are properly charged to the pre determined polarity so that they have no injurious influence upon the operation of the signal receiving device. At the central station likewise a register 71 is provided to receive the telegraphic signals from the devices 50. It may be stated, of course, that when the key 59 is initially closed, whereby current is placed on the line of the proper polarity the same as the last impulse, that this is continued long enough before the counting pole changer is operated, to charge the condensers at the receiving station to prepare the signal receiving devices to properly receive their first step. Of course, the time interval required is extremely short,depending on the time constant of the circuit in bridge of the line. By maintaining the sending battery closed to line after impulses have ceased the condensers at receiving stations cannot discharge, even though there be a large leak between the line wires. This fact permits of successful operation even on poorly insulated lines.

WVhile I have herein shown and particularly described one form of carrying out my invention, I do not mean to limit myself to such specific description and illustration, but

Having thus described one embodiment of my invention, what I claim as new and desire-to secure by Letters Patent is:

1. A signaling system having a central station and substations united by a line circuit, a step-by-step signal receiving device having. an operating winding provided at each substation, a common battery at the central station adapted for normally permitting association with said line circuit, means associated with each signal receiving device to obstruct the operative flow of common battery current therethr gh, m ans at the central station: to control theoperations of said step-'by-step device, said last aforesaid means including a pole changer to transmitcycles of current, each cycle having a positive and anegative impulse, said pole changer when normally at rest serving to establish line conditions to charge the substation condensers with a polarity similar to the polarity of the lastimpulseof each cycle,

and said common battery when associated with said line circuit serving to charge said condensers to the same polarity.

2. A signaling system having a central transmit cycles of current, each cycle having a positive and a negative impulse, said pole changer when normally at rest serving to es tablish line conditions to charge the substation condensers with apolarity similar to the polarity of the last impulse of each cycle, andsaid common battery when associated .with said line circuit serving to charge said condensers to the same polarity.

3. A signaling system comprising a central station andsubstations united by a line circuit, a step-by-step. signal receiving device at each substation having an operating winding, a condenser in series with. the winding of each signal receiving device, means at the central station to transmit cycles of operating current having impulses of opposite polarity to operate. saiddevice, and means to normally charge said condensers of the polarity of the last impressed polarity. a

4:. A signaling system having central station and substations united by a line circuit, a step-by-step signal receiving device having an operating windingvprovided at each substation, a common battery at the central station adapted for normally permitting association with said line circuit, a condenser serially associated with said step-bystep device to prevent thevfiow-of common battery current therethrough, means at the central stationto control the operations of said step-by-step device, said last aforesaid means including a pole changer to transmit cycles of current, each cycle having a positive and a negative impulse, said pole changer when normally at rest serving to establish line conditions to charge the substation condensers with a polarity similar to the polarity of the last impulse of each In Witness whereof, I hereunto subscribe cycle, said common battery when associated my name this 5th day of April, A. 1)., 1912. with said line circuit servin to charge said condensers to the same gi olarity, and a OTIO M switching device to control the association \Vitnesses:

of said pole changer and said common bat- MAX V. ZABEL,

tery With said line circuit. HAZEL JONES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ratents.

Washington, D. 0. i 

